The present application is at least applicable to so-called cavity wall construction. Cavity walls may be composed of two wythes of masonry, usually brick and concrete block, which may be secured together by, for example, metal ties and spaced apart by a cavity between the wythes. The inner wall may be constructed from wood with an inner surface of drywall, structural clay tile, vertical stacks of mortared bricks or blocks, or a shear concrete surface, for example. The outer wall is typically formed of bricks and held together by mortar. A space, or cavity, exists between the two walls, in part for drainage purposes and which may also be partially filled with insulation. It is Applicant's understanding that the Brick Institute defines a “cavity wall” as having a space greater than about 2 inches but not more than 4 inches between the wythes. However, the present application is useful in spaces between inner and outer walls spaced apart less than 2 inches, and more than 4 inches.
In conventional cavity wall construction, flashing is typically installed atop the foundation and weep holes are formed to collect moisture and drain the cavity. Moisture may penetrate the exterior wythe of the wall through a number of places, including top caps, copings, sills, windows, and may penetrate the wall itself through cracks or weaknesses, for example. It is well established that moisture is undesirable in brick or similar wall construction. The presence of water in freezing temperatures may cause cracks in the wall when water expands as it freezes. Trapped water may cause discolorations and other problems, and may even migrate into the dwelling. Another hazard of failing to deal with water is the formation of mold. It is widely accepted that mold growth can damage a building or render the building uninhabitable for various reasons. These reasons include a dangerous situation where the mold growth produces toxins and/or allergens sufficient to sicken inhabitants.
To overcome the problems associated with trapped water, weep holes are commonly included along the base of the outer side of and in the lowermost course of bricks or other masonry units. The weep holes allow water to pass from inside the wall. Also, the weep holes permit water to drain outside the wall structure. A flashing disposed in the wall cavity directs the collected water toward the weep holes.
A problem of cavity wall construction occurs during construction of a cavity wall, when excess mortar and other debris falls into the cavity. When the bricks or blocks are stacked during the erection of the wall, for example, mortar droppings are squeezed into the cavity. The excess mortar materials, as well as other debris, such as insulation, drops to the base of the cavity, and can block weep holes. The same problem can reduce the effectiveness of flashing. To address this problem, inserts, generically referred to as a cavity mortar collection device, may be used in the cavity. Successful devices designed to address the problem of moisture and debris in cavity wall construction are shown, for example, in U.S. Pat. Re. 36,676, incorporated herein by reference.